Interfacial reactions of Ni-Ta thin films on GaAs

A. Lahav*, M. Eizenberg

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

The interfacial reactions between Ta-Ni thin films and (100) GaAs substrate have been analyzed by Auger electron spectroscopy, x-ray diffraction, and transmission electron microscopy. A pure Ni film reacts with GaAs at 250°C forming a ternary Ni2 GaAs epitaxial compound, which at 600°C dissociates to NiGa and NiAs. Ta interacts with GaAs only at 650°C. In the case of a Ta/Ni film on GaAs at temperatures up to 450°C only the Ni layer reacts with the substrate forming Ni2GaAs. At higher temperatures the dissociation of Ni2GaAs combined with As outdiffusion results in the structure TaAs/NiGa/GaAs. For the complementary Ni/Ta bilayer, the Ta/GaAs interface is intact up to 500°C; at this temperature only Ni-Ta intermixing takes place. At 600°C, Ni penetrates into the interface with GaAs and forms NiGa. The reaction of the alloy film Ni60Ta 40 with GaAs starts at 450°C by Ni leaching out of the alloy and forming Ni2GaAs at the interface with GaAs. At higher temperatures the reaction results in a structure similar to that obtained for the bilayers with NiGa adjacent to the GaAs substrate. The potential applications of the studied metallization schemes for contacting to GaAs are also discussed.

Original languageEnglish
Pages (from-to)256-258
Number of pages3
JournalApplied Physics Letters
Volume45
Issue number3
DOIs
StatePublished - 1984
Externally publishedYes

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